Various detachable fairings reveal the position of internal mechanical and electronic components . Those fairings may disturb in some extend the smooth flow over the car body but allow mechanics to access mechanical parts without removing the entire sidepod covering .
At China a small single vertical flow guide was added on top of the sidepod to counter fight the lift created by sidepod’s shape which resembles to a down facing winglet . These vertical vanes are common in F1 since a long time ago. For example Caterham current cars race with a combination of three .
In addition to changes concerning C31 cooling, many other revisions took place on the car before Melbourne . The rear silhouette of the sidepod tunnels was heavily modified after launch at Jerez test . The new longer tunnels expand smoothly to reach floor level in a such way to guide more drastically the exhaust gases towards the inside area of the rear wheel profile and reach the diffuser . To enhance the effect further, a channel is sculpted behind the periscope exhausts and later at Barcelona test on February a vertical fence was added on the floor along the route of the hot gases.
Speaking for the rear floor morphology , it was reshaped twice with the first revision to take place at Jerez alongside with the sidepod expansion to the rear and the second revision at Barcelona on March with the trapezoid channel in front of the rear wheel to be replaced by a small duct .
A promising update for the team which took place also at Barcelona on March , was the connection of the sidepod panel to the chassis via a wavy winglet to force air flowing above the sidepod profile to follow the shape outline of the sidepod stronger and increase the downwash effect of exhaust gases to the diffuser .
Some interesting but important details on C31 are also the following
-a small duct , already present since launch , permits a small portion of air flowing under the floor to find exit above the floor level instead of bleeding to the sides .In some occasions the duct was partially covered with tape
– a cooling duct for KERS components is spotted at left side only of the sidepod bottoms
-briefly Sauber tested a set of gills around the launch spec periscope exhausts
- Sauber C31-Sidepod panels (formula1techandart.wordpress.com)
- Sauber C31 – cooling options tested during Winter testing (formula1techandart.wordpress.com)
- Sauber C31 – Rear end improvements at Jerez test (formula1techandart.wordpress.com)
- Sauber C31 – rear end details (formula1techandart.wordpress.com)
- Sauber C31 – Australian front wing (formula1techandart.wordpress.com)